1. Field of the Invention
The present invention generally relates to data processing and, more particularly, to creating queries using linked result fields.
2. Description of the Related Art
Databases are computerized information storage and retrieval systems. The most prevalent type of database is the relational database, a tabular database in which data is defined so that it can be reorganized and accessed in a number of different ways. A distributed database is one that can be dispersed or replicated among different points in a network. An object-oriented programming database is one that is congruent with the data defined in object classes and subclasses.
Regardless of the particular architecture, a DBMS can be structured to support a variety of different types of operations for a requesting entity (e.g., an application, the operating system or an end user). Such operations can be configured to retrieve, add, modify and delete information being stored and managed by the DBMS. Standard database access methods support these operations using high-level query languages, such as the Structured Query Language (SQL). The term “query” denominates a set of commands that cause execution of operations for processing data from a stored database. For instance, SQL supports four types of query operations, i.e., SELECT, INSERT, UPDATE and DELETE. A SELECT operation retrieves data from a database, an INSERT operation adds new data to a database, an UPDATE operation modifies data in a database and a DELETE operation removes data from a database.
Queries may include both an explicit specification of result fields for which data is to be returned upon execution of the queries, and criteria used for selection of the data. The data selection criteria are generally represented as query conditions that serve to filter the data returned for the result fields upon execution of the query. Accordingly, a query may be thought of as group of filters put together to sift out only the result field data in which they are interested.
Result fields of queries can be linked to each other such that analysis of information obtained for a given result field requires analysis of information obtained for corresponding linked result fields in order to determine a meaningful analysis result. For instance, assume a quality control environment where a specific quality control consists of a multiplicity of individual tests performed on corresponding objects. Each result obtained for an individual test can be described by an associated quality control field. All associated quality control fields are linked to each other as they all relate to the specific quality control. Assume now a user who wants to verify whether the specific quality control has been performed for a given object and whether the result of the quality control was acceptable. Therefore, the user may create a query to retrieve the results of all individual tests performed on the given object. To create the query, the user manually includes all associated quality control fields as result fields with the query. However, if the number of associated quality control fields is large, this process is cumbersome and time-consuming.
Therefore, there is a need for an efficient technique for creating queries including linked result fields.